Propylene is an important commodity chemical, widely used to produce plastics, rubbers, fibers, and films. Propylene is also used in the production of polypropylene, acrylonitrile, and propylene oxide. In 2013 alone, approximately 85 million tons of propylene was processed worldwide.
Propylene is commonly produced as a byproduct during the steam cracking of naphtha and oil and during the fluid catalytic cracking used to produce gasoline and ethylene. As the commercial demand for propylene increases, maximizing the yield of propane has become increasingly desirable. In particular, propylene can be generated through the catalytic dehydrogenation of propane, which is one of the major components of natural gas (shale gas) or liquefied petroleum gas.
The dehydrogenation of propane to propylene is a highly endothermic process, often requiring high temperatures and the use of a catalyst. Major catalysts used in the industry for catalytic dehydrogenation of propane include alumina-supported platinum-tin based catalysts. Such catalysts are both highly active and selective, but are susceptible to coke deposition and deactivation during catalysis. Use of such alumina-supported platinum-tin catalysts requires frequent regeneration to recover catalytic activity, which increases off time during the dehydrogenation reaction.
U.S. Pat. No. 3,978,150 discloses a continuous process for the dehydrogenation of propane to minimize reactor downtime. This technology utilizes a complicated cyclone reactor design to allow the continuous removal of deactivated catalyst from the reactor and continuous regeneration and feeding into the reactor, which could increase capital and operation costs. Additionally, this process does not improve the stability of the catalyst, which is highly desired.
The disclosure herein is directed to overcoming these and other deficiencies in the art.